The present invention relates to a conveyance apparatus to convey a transfer sheet, onto which an image is transferred at a transfer processing section, in an electronic copier or the like.
In an image forming apparatus such as a copier and the like, the following operations are conducted: a document image is exposed on a photoreceptor; the image on the photoreceptor is developed and a toner image is formed thereon; the toner image on the photoreceptor is transferred onto a transfer sheet in the transfer processing section; and further, the toner image is fixed on the transfer sheet after heating and pressing operations are performed. As a conveyance apparatus used for the foregoing image forming apparatus, one example of the apparatus includes a conveyance unit provided to a rear part of the transfer processing section by which the toner image on the photoreceptor is transferred onto the transfer sheet. Conveyance rollers are provided between the conveyance unit and the transfer processing unit so that the transfer sheet is guided from the transfer processing section to the conveyance unit through the conveyance rollers. For example, the foregoing conveyance apparatus is described in Japanese Published Patent Application No. 125075/1983, and Japanese Published Utility Model Application No. 31435/1977.
As described above, when the conveyance roller is used in order to smoothly guide the transfer sheet to the conveyance unit, transfer slippage at the transfer processing section is prevented. However, since the position of the conveyance roller is fixed, its line speed is not regulated. Additionally, since conveyance apparatus has only a guiding function by which the transfer sheet is supported, conveyance properties are deteriorated, the transfer sheet can not be appropriately conveyed, and transfer slippage can not be sufficiently prevented with respect to both thick paper and regular paper.
In view of the foregoing problems, the object of the present invention is to provide a conveyance apparatus by which conveyance properties of the transfer sheet are improved, and transfer slippage is prevented.